Traditionally smartphones in the U.S. cost anywhere from nothing (free) to a couple hundred dollars. The true cost of these smartphone devices can be $600 USD or more. But carriers have transferred that cost to customers over the life of the plan via higher service bills.

It's long seemed a clever psychological gambit; tricking customers into thinking they're paying less. But it's not one that everyone is happy with. Of late opposition to the subsidy model has been mounting. And T-Mobile USA is leading the critics.

Starting today you'll be able to buy an unsubsidized handset from the carrier or elsewhere and then build a service package buffet-style that works for you.

Pricing varies based on the amount of data you select (500 MB, 2 GB, 4 GB, 6 GB, 8 GB, 10 GB, 12 GB, and unlimited options are possible). For the 500 MB option you get that, plus unlimited talk and text for $50 USD/month. For $20 USD you get "unlimited" data (no overages), while for each $10 USD more, you get 2 GB of unthrottled data.

II. What Do You Gain? What Do You Lose?

So how does this stack up to other carriers? You have to remember; you're not getting your handset subsidized.

With that in mind let's consider a 1 GB data contract with unlimited talk and text. On the nation's largest network -- Verizon Communications Inc. (VZ) and Vodafone Group Plc.'s (LON:VOD) joint-subsidiary Verizon Wireless -- you get this for $90 USD/month on a two-year contract. The same contract is $60 USD/month on T-Mobile. So you save $720 USD over the course of the two-year contract by picking T-Mobile.

Most premium smartphones on T-Mobile fall in the $400-500 USD range, so even with the cost of the phone, you'll still come out a couple hundred dollars ahead. Plus T-Mobile USA does offer financing to essentially lessen the blow of paying for your new phone up front. There's (of course) a small fee (interest) involved, but overall it's not as bad as a subsidized plan.

Also recall that T-Mobile subscribers are now "free" and can leave at any time -- versus subsidized contract customers on other networks who face incremental cancellation fee penalties for jumping ship before the contract's 2 years are up.

Buying handsets like the HTC One may be expensive unsubsidized, but T-Mobile's pricing scheme will save you significantly over the course of your contract.

So the upsides are being contract free, saving money, and having a more clear perspective on what you're paying for service versus what you're paying for hardware.

About the only downsides are that you do have to pay up-front, and more importantly that T-Mobile's HSPA+ 3.5G network leaves something to be desired in terms of coverage and speed. T-Mobile has promised an aggressive LTE rollout this year to catch up with rivals Verizon, Sprint Nextel Corp. (S), and AT&T, Inc. (T), but it's premature to assume it will achieve its ambitious goals for that push.

Regardless, if you want the best contract price-wise T-Mobile is the place to be (or possibly one of Sprint's various pre-paid brands). With handsets like the HTC One by HTC Corp. (TPE:2498) and the Galaxy S IV by Samsung Electronics Comp., Ltd (KSC:005930) incoming, T-Mobile may see a strong pickup if it can properly advertise just how good a deal it's giving U.S. customers.

I like what T-mobile is doing. I think differentiation will be good for them. I just hope they know how to sell it properly. I tried explaining the difference between the European model and American model of phone selling to my brother (a fairly tech-literate person) but for some reason he didn't seem to understand it. If T-mobile can show people that they're saving money, then they could pick up a lot of customers.

Also, aggressive marketing of the HTC one would be good for both HTC and T-mobile.

I think they will let you move plans, because you have always been able to move plans within T-Mobile, however keep in mind that your current plan might be better than the new one. T-Mobile has removed the minute based plans and made everything unlimited text and talk, so the $20 discount some people get for using the 1500 minute plan is unavailable anymore.

Overall they are still the better price and they did reduce the international talk and text to $10 a month.

Well, I just asked my wife to call them and see. She just signed a 2 year contract a few months ago. Fingers crossed because she is paying about $110 per month and if we can get it down to $60+ tax/fees that would be awesome!

So here is the deal. We can pay a $200 migration fee, or we can wait till May 2014 and switch. By my math we can save about $320 if we pay the $200 fee and switch to the $60 plan, assuming that it would come to about $70 after taxes and fees.

Might still be $110 a month including fees if she is paying the extra $20 per month for monthly payments on the phone, $20 per month for unlimited data, and $7.99 per month for premium handset protection. The best you can do is drop the $20 per month for unlimited data which should still default to the 500mb data plan, but not confirmed.

She will only have to pay for the phone in monthly installments if she doesn't pay the $200 fee. The whole point of the $200 fee to get out of contract is to mitigate the cost of the phone. Once she pays the $200 fee, she doesn't have to pay monthly installments for the phone too.

I have to be pessimistic about this one. Here in europe all carriers offer pre-paid and subsidized subscriptions. The people also know pre-paid is alot cheaper. Even so the vast majority of smartphone users are still younger people (it'll take another decade before the smartphone generation hits disposable income) who can't afford 500 euro's up front. So the vast majority of phones are bought on contract.

Even so, i recently bought a pre-paid smartphone of about 350 euro's. T-mobile has the largest selection of the carriers in my country but thing is - i didn't buy it from a carrier. That's silly. I bought it from a webshop, a so called "box shoveller" like amazon who just buys massive quantities to sell on margin. Would've cost me almost 100 euro's extra if i'd bought it at t-mobile.

Ysee the thing is people buying pre-paid are already looking to save money so they will try to save the most money possible (this is logical, you have to have saved the money upfront to buy prepaid in the first place). Which is webshop + sim only subscription, and has always been.

If i'd had to wager a guess "why now" t-mobile is starting to offer this deal, i'd point at the trillion+ dollars in student loan debt. Students are probably the biggest section of the smartphone market. They don't have money so they're all on contracts. Since tuition and such is going up, that leaves less credit - or money that can be paid monthly instead of upfront - to spend on smartphones. I'd suspect the carriers have already seen a significant drop in sales because of this, and it's always the small fish that blink first as their margins for error are smaller.

In other words T-mobile wants to get a piece of the people who do still have money, because the people who don't have money are running out of possible money.